1. Field of the Invention
The present invention relates to a process cartridge and an image forming system on which such a process cartridge can be mounted. Such an image forming system may be embodied, for example, as an electrophotographic copying machine, a laser beam printer, a facsimile, a word processor or the like.
2. Related Background Art
In image forming systems such as copying machines, a latent image is formed by selectively exposing an image bearing member that is uniformly charged. The latent image is then visualized with toner, and then the toner image is transferred onto a recording sheet, thereby forming an image on the recording sheet. In such image forming systems, whenever the toner is used up, new toner must be replenished. The toner replenishing operation not only is troublesome, but also often causes contamination of the surrounding components. Further, since the maintenance of various elements or members an be performed only by an expert in the art, most users feel inconvenienced.
To eliminate such drawbacks and inconvenience, an image forming system wherein parts such as a developing device in which toner is used up or an image bearing member for which a service life thereof has expired can easily be exchanged, thereby facilitating the maintenance, by assembling the image bearing member, a charger, the developing device and a cleaning device integrally formed as a process cartridge which can be removably mounted within the image forming system has been proposed, for example, as disclosed in U.S. Pat. Nos. 3,985,436, 4,500,195, 4,540,268 and 4,627,701.
In such a process cartridge, the charger is constituted as a single charger unit comprising a charger wire for generating corona discharge and a shield plate. Further, the developing device is constituted as a single developing unit comprising a developing sleeve, a developing blade, a toner feed mechanism, a toner-containing portion and a developer container. Further, the cleaning device is constituted as a single cleaning unit comprising a cleaning blade, a toner squeegee sheet and a cleaner container.
However, in the above-mentioned conventional techniques, there are the following problems:
In view of the protection of the earth-environment, it has been strongly requested to collect the used-up cartridges and re-use (re-cycle) them to effectively utilize the resources. To this end, when the process units are formed independently, the disassembling and cleaning of the process units to re-use them requires a number of various steps, thereby increasing the difficulty of the re-cycling operation.
Further, in order to efficiently re-cycle the process cartridges, it is necessary to disassemble and clean the used-up process cartridges collected from the market efficiently.
For this purpose, the inventors have created the effective invention which could eliminate the above-mentioned problems and filed as previous Applications (Japanese Patent Application No. 2-301779, U.S. Ser. No. 785,401, EP-A 91/402953.3, Chinese Patent Application No. 91111554.4 and Korean Patent No. 91-19663).
The present invention relates to an improvement in the invention described in the aforementioned previous applications, whereby used-up process cartridge collected from the market can be disassembled and cleaned efficiently.